Commit 06d07139 authored Jun 27, 2014 by Oleg Nesterov Committed by Steven Rostedt Jun 30, 2014

uprobes: Change unregister/apply to WARN() if uprobe/consumer is gone

Add WARN_ON's into uprobe_unregister() and uprobe_apply() to ensure
that nobody tries to play with the dead uprobe/consumer. This helps
to catch the bugs like the one fixed by the previous patch.

In the longer term we should fix this poorly designed interface.
uprobe_register() should return "struct uprobe *" which should be
passed to apply/unregister. Plus other semantic changes, see the
changelog in commit 41ccba02.

Link: http://lkml.kernel.org/p/20140627170140.GA18322@redhat.com



Acked-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

parent 48212542

kernel/events/uprobes.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -846,7 +846,7 @@ static void __uprobe_unregister(struct uprobe uprobe, struct uprobe_consumer u
		{
		int err;

		if (!consumer_del(uprobe, uc)) /* WARN? */
		if (WARN_ON(!consumer_del(uprobe, uc)))
		return;

		err = register_for_each_vma(uprobe, NULL);
		@@ -927,7 +927,7 @@ int uprobe_apply(struct inode *inode, loff_t offset,
		int ret = -ENOENT;

		uprobe = find_uprobe(inode, offset);
		if (!uprobe)
		if (WARN_ON(!uprobe))
		return ret;

		down_write(&uprobe->register_rwsem);
		@@ -952,7 +952,7 @@ void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consume
		struct uprobe *uprobe;

		uprobe = find_uprobe(inode, offset);
		if (!uprobe)
		if (WARN_ON(!uprobe))
		return;

		down_write(&uprobe->register_rwsem);